Dental unit waterlines are all the rage these days - whether that's because of the new research coming out or because they can be the cause of rage for dental pro's is another discussion.
On the surface, it can seem easy to tell the treatment options apart. Application, cost, and longevity are all important factors when selecting a waterline treatment solution.
But first, you want to know if the product you're spending money on will work.
After all, getting dental unit waterlines clean so you can deliver safe water into your patients' mouths is why you're working on waterline maintenance protocol in the first place!
The Largest Waterline Treatment Efficacy Study to Date
In 2017, ProEdge conducted the largest dental waterline treatment efficacy study to date. This study has been cited in a peer-reviewed article by John A. Molinari, PhD and Nancy Dewhirst, RDH, BS. Compiling data from over 22,000 consecutive waterline tests, this study shows important real-world statistics of product performance in the marketplace.
Of these 22,000+ consecutive waterline tests, all samples were taken directly from clinical practices and provided by those practices. Treatment information was provided by the dental practices as well.
Every sample was tested using the R2A heterotrophic plate count method. All tests were blind and utilized ProEdge's gold-standard methods to ensure accuracy. All pass/fails were measured against the standard for safe water of ≤500 CFU/mL set by the Centers for Disease Control (CDC).
Key Findings from the Study
Overall, 31% of treated waterlines failed to meet the CDC Standard of ≤500 CFU/mL.
Tablets with an accompanied shock product showed the best results. A handful of product combinations were above 90% pass rate, however these did not have very large data sets.
Straws and cartridges passed at 72% on average.
Shock treatments used by themselves – with no accompanied continuous or daily treatment products – performed similarly well to daily liquids and centralized systems at 60% or below (Note: Sterisil Systems performed significantly higher than other centralized systems at 70%. The next highest was 40% and some were lower than 25%).
No treatment product without an accompanied shock treatment passed above 90%.
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How Can Treated Waterlines FAil This Often?
This is for a few reasons. But first, let's be clear: most of the products used in dental practices across the world are great products.
Each of the treatment types and specific products have features and benefits that can be appreciated. But often, how products are sold is different than how they work in the real-world.
These are the most common reasons we've found for poor performance:
- Sold with Unrealistic Expectations
- Misunderstanding the science of low-level antimicrobials vs biofilm
- Poor Product Instructions-for-Use (IFU)
- Underlying equipment issue
(1) Products are often sold as maintenance-free, and unfortunately, none of them are.
A quick review of the IFUs show each product requires close attention and a little elbow grease to be effective. Whether that involves testing your water hardness, daily water bottle drying, monthly water bottle washing, or performing a protocol multiple times to start, make sure you review the instructions-for-use on a manufacturer's website to know what a product requires.
If you do that, you'll see it's never just twist or drop and you're done. For example, ProEdge's waterline maintenance tablet BluTab® requires shocking your waterlines at regular intervals to be most effective. Which leads us to the next point.
(2) There are two kinds of dental waterline treatment products: continuous treatments (low-level antimicrobials) and shock treatments (high-level disinfectants).
Continuous treatments contain low-level antimicrobials that maintain already clean lines while also being safe for patient contact. They continuously fight bacteria within the lines.
- A-dec's ICX®
- DentaPure Straw
- DentaPure Cartridge
- Sterisil Straw
- Sterisil Cartridge
- Z3 Tablet
- Patterson Tablet
- Sodium hypochlorite solution (diluted bleach)
- Crosstex Liquid Ultra™
Shock treatments clean the waterlines. Continuous products maintain the already clean lines for longer before another shock treatment is required. When used together, pass rates go way up. When used separately, results are wildly inconsistent.
(3) Some products have instructions-for-use that suggest shocking and testing are not necessary for safe waterlines.
The data from this study proves otherwise. ProEdge highly recommends using both a shock treatment and a continuous treatment, even if sales literature says you do not need to. If you're suspicious, test your waterlines quarterly with a recommended method so you know your treatment is effective.
(4) Lastly, and this is much less common, there can be an underlying equipment issue that can lead to poor failure rates.
Sometimes, it can be as simple as an unknown toggle that switches some devices between sources (municipal or independent water bottles). We've also seen some very old waterlines that have been building up biofilm for years. Other times, it can be dead legs that create stagnant water perfect for biofilm development that feed bacteria into the other lines and overwhelms the products. Sometimes it can be a filter or other problem.
What Should our Practice Do?
Each practice is different and should choose the right treatment protocol based on those unique needs. And again, each of these product types can be very effective.
It's just that they can fail, too. Unfortunately, there is no waterline maintenance silver bullet.
There is however, three steps you can take to ensure your practice has a proven protocol.
- Balance Effectiveness with Convenience - review product IFUs closely to see what is required.
- Combine Continuous with Shock - always use both a shock treatment and a continous treatment if you want consistently safe waterlines.
- Test Quarterly - it's the only way to know if what you're doing is working.
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Tips & Tricks, Est. Cost, Est. Use, Efficacy Rates
For a deeper dive into waterline treatments, Read on...
Continuous Treatments (Maintenance Products)
All of the FDA or EPA registered continuous treatment products available on the market today utilize low-level antimicrobials to control microbial growth. The most popular of which utilize silver and iodine chemistries. These low-level antimicrobials are generally in a concentration of in parts per million (PPM). Similarly, Chlorine is often used in city water and pools to control bacteria is typically 1-2 ppm. Iodine-based products are typically .5 – 4 ppm and silver based technologies are typically .5-1 ppm.
These low-level antimicrobials are designed to be continuously present in your dental waterlines to constantly attack bacteria. These can be introduced into your lines by three standard methods: tablets, cartridges, and daily liquids. Because they are continuously present in the lines as well as the irrigant water (procedural water) and sprayed in the patient’s mouth, they are by necessity designed to have very low concentrations of antimicrobial agents for patient safety.
Continuous treatments are used to maintain already clean lines allowing you to go longer periods without shocking.
Unfortunately, the failure rate of all of treatment products together is still 31%. The reason is that following the instructions for use are critical. Compare that to sterilizers used on instruments where the fail rate is only 1.5%. Whichever water treatment product you select, it is important that you carefully follow the instructions and test your maintenance protocol at least quarterly to ensure success.
Shock Treatments (Cleaning Products)
The shock product category is comprised of high level disinfectants. They can remove well established biofilms even in dental units that have been operated for years without being subjected to any antimicrobial treatments. They effectively clean the waterlines of bacteria and biofilm.
Since bacteria will multiply within a few days, routine treatment with a shock product as the only treatment requires weekly shocking of every line. And simply because a shock treatment was implemented does not mean the waterline is clean. It can take several shock treatments depending on the level of contamination within your waterlines. Test to ensure you shock protocol is effective and to determine the correct frequency.
Continuous Treatment Products
The most popular treatment method is a tablet that is added to the independent reservoir each time it is refilled with water. Roughly 11 million tablets are used by U.S dentists each year. This the most common method of treating dental unit waterlines. If you consumed 200 liters per operatory per year the annual cost would be $91 (200 liters x .45 cents per 2 liter tablet). Simply, it's economical and one of the more effective treatment types.
Cartridges are small resin filled with iodine or silver chemistries that release a low-level antimicrobial into the water as water passes through the cartridge. They are designed to replace the take-up straw in your independent reservoir. Cartridges range in cost from $245-252 per year per operatory. The most popular straw is designed to last for 1 year or 240 liters of water, whichever comes first.
Daily liquids is a category that includes Chlorhexidine Gluconate, citrus botanicals, and chlorine dioxide based chemistries. They are added to the independent water bottle each time it is refilled. This one of the least popular methods and accounts for about 5% market share. The costs per year range from $104 to $217 per operatory.
The most popular shock products are diluted household bleach and Crosstex Liquid Ultra. Both products are effective at removing/killing biofilms. Many OEM equipment manufacturers recommend diluted bleach or sodium hypochlorite (13 parts water to one-part bleach). Crosstex Liquid Ultra is a quaternary ammonium compound and hydrogen peroxide based chemistry. Shock products make up 4% of the market. The cost to treat an operatory for a year ranges from $3 for bleach and around $117 for Crosstex Liquid Ultra.
Selecting the Right Waterline Treatment Protocol
The vast majority of the dentists use tablets and straws. The main reason is tablets and straws (continuous treatment) are economical, can provide good results and are convenient. Straws and tablets will inhibit the proliferation of bacterial growth and ultimately biofilms, but they will not render the lines and water sterile.
Tablets are effective as long as you follow the instructions. Tablets require a periodic shock (every 1 to 3 months). Add a tablet every time you refill the water bottle. Shock your dental unit waterlines as recommended by the manufacturer and test for microbial counts regularly. Tablets combined with at least quarterly shocking provides highest level of effectiveness.
Cartridges are represented as having one-year use-life. Cartridges are an effective method of delivering low level antimicrobials. Always start the use of a cartridge with clean/shocked lines. Cartridges manufactures instructions for use include important parameters on the hardness of the water, concentration of chlorine in source water, the temperature of the water. Follow the instructions. Failing to do so can result in a failure to meet the ADA/CDC standard for clean water. Test water quality quarterly.
This class of product is about 5% of market and does provide low level antimicrobials to the dental unit waterlines, however, the data indicates that the actual effectiveness results are the lowest category tested. Do your research, follow instructions and test for microbial counts quarterly to verify performance.
Shock products used correctly are very effective. Follow the IFU’s and test regularly. If you use household bleach, a 13 to 1 dilution and 10 minutes or less exposure time is recommended.
Is Your Treatment Working?
Waterline testing research shows that even with the most effective dental water treatment products, the possibility of microbial contamination remains relatively probable. That's why regular waterline testing is a vital part of any waterline maintenance protocol.
"The only way to ensure effectiveness of a dental unit waterline cleaning regimen is to actually test the water coming out of the unit." - American Dental Association
We recommend all dental clinics test their dental waterlines quarterly to ensure dental water treatments are working properly and your patients and practice are safe.
All of the statements in this article are based on the data from 22,196 consecutive water tests conducted by ProEdge Dental Water Labs in 2017. ProEdge has been testing dental water for 15 years and works closely with dental offices to correct failed water tests. The effectiveness data is derived from test data provided by hundreds of dental practices. The data is reported in this article the same way it is reported to our lab. The data contained in this paper is based on 22,196 water tests and indicates how a product is performing in the marketplace. It does not guarantee that any particular product will perform exactly as the effectiveness data is reported. For more detail information on dental unit water testing, contact our team or call today at 888.843.3343.